_Van_Biesbroeck.png) Van Biesbroeck modeled from itslightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | A. Kopff |
| Discovery site | Heidelberg Obs. |
| Discovery date | 17 October 1906 |
| Designations | |
| (1781) Van Biesbroeck | |
Named after | George Van Biesbroeck (astronomer)[2] |
| A906 UB · 1954 SZ 1958 VP · 1969 TM2 | |
| main-belt · Vestian[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 110.55 yr (40,377 days) |
| Aphelion | 2.6541AU |
| Perihelion | 2.1355 AU |
| 2.3948 AU | |
| Eccentricity | 0.1083 |
| 3.71yr (1,354 days) | |
| 330.79° | |
| 0° 15m 57.24s / day | |
| Inclination | 6.9497° |
| 44.630° | |
| 342.83° | |
| Physical characteristics | |
| Dimensions | 8.500±0.126[4] 9 km(estimate at0.20)[5] |
| 0.203±0.023[4] | |
| XS[3] | |
| 12.75[3] · 12.8[1] | |
1781 Van Biesbroeck (prov. designation:A906 UB) is aVesta asteroid from the inner regions of theasteroid belt, approximately 8.5 kilometers in diameter. It was discovered on 17 October 1906, by German astronomerAugust Kopff atHeidelberg Observatory in southern Germany.[6] It was named after astronomerGeorge Van Biesbroeck.[2]
Van Biesbroeck orbits the Sun in theinner main-belt at a distance of 2.1–2.7 AU once every 3 years and 9 months (1,354 days). Its orbit has aneccentricity of 0.11 and aninclination of 7° with respect to theecliptic.[1] It is not known whether the member of theVesta family of asteroids is in fact aV/J-type, or if it is an unrelated interloper, as currently assumed to be more likely.[3] The asteroid'sobservation arc begins with its official discovery observation, as noprecoveries were taken, and no previous identifications were made.[6]
According to the survey carried out by NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission,Van Biesbroeck measures 8.5 kilometers in diameter, and its surface has analbedo of 0.203.[4] A genericabsolute magnitude-to-diameter conversion gives an inferred diameter between 8 and 14 kilometers, assuming analbedo in the range of 0.05 to 0.25 for an absolute magnitude of 12.8.[5] As of 2017,Van Biesbroeck's composition,rotation period and shape remain unknown.[1][7]
Thisminor planet was named after renowned Belgian–born observational astronomerGeorge Van Biesbroeck, who naturalized as U.S. citizens in 1922. He specialized in the observation ofdouble stars,variable stars,comets and asteroids, of which he discovered sixteen at the U.S.Yerkes Observatory in Williams Bay, Wisconsin, between 1922 and 1939.[2] The officialnaming citation was published by theMinor Planet Center on 1 January 1974 (M.P.C. 3569).[8]
In 1961, he published theVan Biesbroeck's star catalog of low-mass, low-luminosity stars. The mountainVan Biesbroeck near theMcDonald Observatory, the lunar craterVan Biesbroeck, and most notably the red dwarfVan Biesbroeck's Star, were also named in his honour. (There are very fewstars named after people). TheGeorge Van Biesbroeck Prize, awarded by theAmerican Astronomical Society for achievements in astronomy, also bears his name.
